Scary Handling Problem

[DunnInn]

First the equipment:
2009 Winnebago 29T class C on 2008 Ford E450 with V10 Triton
2007 Jeep Liberty with 4 wheel drive
Blue Ox Tow Bar and Tow Plate
Brake Buddy

Now the problem:
When driving the Winnebago or Jeep separately, they do fine. When you hook them together, it becomes a white knuckle experience. When the toad is hooked up, driving at city speeds, the steering on the RV seems stiff and doesn’t try to return to center after a turn. With the toad hooked up, driving at highway speeds, when I try to correct for a wind gust or a truck passing, the RV seems sluggish in responding then overcorrects and must be corrected back. This leads to overcorrection to the left followed by overcorrection to the right and this continues for several cycles. Then it’s back to a constant wandering between the lines. The tow bar handles are both in the locked position and there is no slippage in the bar. The alignment on the Jeep checked out OK. Also had the shocks on the RV checked – they’re OK. No oversized tires on the vehicles. Sure would like to find an INEXPENSIVE solution to this problem. Any suggestions?

[j-d]

I really don't know what Winnie's justification for not stretching your chassis more than they did could be. Stretch Plus Two Feet More in Front of the Axle and Minus Two Feet Behind... Cost would have to be just about a wash.
I've tracked Harvard's progress toward good handling from Day One and what he did with Caster was close to miraculous. Hopefully it'll help you. Still, with all that overhang and the short wheelbase ratio, I'm becoming convinced you're going to need all the help you can build into (under) that coach.

[DunnInn]

Talked to alignment guy yesterday. He's going to set the left caster at 5.3 and the right at 5.8 on Wednesday. Also the toe in increased by 1/8". Fingers crossed!!

[Harvard]

DunnInn wrote:
I'm planning on talking to the guy who did the alignment and asking him to change the caster to 5 - anybody think it should be greater than that? Also any recommendations for online places to order hellwig swaybars? Think that's next. I definitely think the length past the back axle is an issue, but can't change that. Thought we were getting a good deal when we bought this unit. Looks like it's not turning out that way.

I changed my caster from +3.3 to +5.3 (upper specified limit is +7.3) and it made all the symptoms you have talked about go away.

[Kamphiker]

Trac Bar on the rear should have taken away the side push on the rear.

It sounds like the "Tail is wagging the Dog" when the Toad is attached.

Several others have observed / suggested to have your RV weighed to get the tire pressures correct for the actual travel weight.

I'm thinking (as others have stated) that you don't have enough weight on the front axle in relation to the rear, This allows the Toad to steer the RV.

Another thought what is your ride height UN-loaded, fully loaded w/ & W/O the Toad ? (measure the 4 corners top of the wheel wells) Are you squatting Down in the rear a excessive amount when fully loaded ?

[desertrek]

Dunnlnn,
I just looked and my 2011 coach came with front and rear sway control bars from the factory. If yours didn't, that could be a big issue too. I owned one 3/4 ton pickup I bought used that had sway control front only (unusual) until I installed the rear it was terrible towing anything.

[j-d]

For the caster, search for Harvard's posts or send him a private message.

For the Hellwig bars, SD Truck Springs

[DunnInn]

I'm planning on talking to the guy who did the alignment and asking him to change the caster to 5 - anybody think it should be greater than that? Also any recommendations for online places to order hellwig swaybars? Think that's next. I definitely think the length past the back axle is an issue, but can't change that. Thought we were getting a good deal when we bought this unit. Looks like it's not turning out that way.

[Harvard]

++caster...++caster....++caster...++caster

[mikebo]

I have much the same problem that you have, my motorhome has a long rear overhang, a light front end which leads to my toad pushing the rear causing oversteer. I have mitigated the problem by replacing the shocks with bilsteins, adding hellwig sway bars and a blue ox track bar. My motor home has hellwig overload springs on the rear axle, stiffening them seems to help. I carry 60-65 psi in my front tires and 80psi in the rear. I had the front end aligned with more toe than specs. This makes the my motorhome handle ok, not as neutral as with out the toad, but not at all scary.

Mike

[j-d]

Your comment that the overhang looks like half the length of the coach piqued me. I looked up Winnebago 29T and it says length is a little over 30-ft (360") and wheelbase is 190" which is 53% of length. I'd be interested in what the ratio for your friend's Coachmen is. Without year and model, I couldn't look anything up. That's a short wheelbase and low % for driving stability. For example, our 31-ft (372") has a 218" wheelbase for 59%.
Then I read the whole thread again and your weights aren't listed or I missed them. Ford wants that 32% of loaded weight on the front axle. That is going to be VERY hard to achieve with that 53% wheelbase. That much rear overhang is also going to lead to sway, and sway in a Ford chassis causes it to STEER. When you probably want it not to steer or want it to steer in a different direction.
The Track Bar will help, but if your front axle is light and front tire pressures high, it won't have much direcitonal stability.
What's the condition of the front end in the Liberty? When I was transferring the rental trucks we towed my Dodge van and it tracked ok behind an E350 cube van. A friend had a similar van he'd bought used cheap and when we towed it we had a lot of tugging and wandering. We later found most of the front end parts were worn out.
Suggest you review basics. What are your loaded weights, at least by Axle, ideally by Corner? And are your Tire Pressures set according to the Weights? That said, if you only have 27% (example, we don't know yet) on the front axle, the correct tire pressure isn't going to make it track correctly.
desetrek's 88 coach is the old chassis like our 83 E350 and I tweaked our toe in just a little too. Never had it formally aligned, only checked the toe with a couple straight edges and a measuring tape. Contrary to "the book" these Fords drive better with more Caster and more Toe than the specs.

[desertrek]

One more thing you might try. On my 88 Itasca E350 I used to set my own tow in to an extra 1/8" in to the front of the vehicle. Upside is it handled much better especially while towing. Downside was some extra wear on the front tires. I'm not sure how much different the new front ends are but the on old Twin-I beam front ends, the tow in used to move in and out quite a bit as the front bounced up and down. The little extra "Tow In" seemed to help. I decided I would live with the extra wear on the tires for the better handling.

[DunnInn]

Add the toad and it's back to being bad. When you turn the wheel either way it doesn't immediately turn. There is a delay. Then when it finally starts turning, if you take your hands off the wheel it doesn't return to center. So, because of the delay, when you try to get the RV going straight down the road after a try at a correction, you end up zigzagging down the road for quite a while. Any more suggestions?

[DunnInn]

Added the Trac Bar today and it's handling even better. Will try it with the toad tomorrow.

[DunnInn]

YEAH!!! Put on the Safe-T-Steer today and took it out for a drive. MUCH BETTER!! Trac Bar tomorrow - hopefully that will take care of ALL of the problems. We did look at how much of the RV was hanging over the rear wheels and it looks like about 50% - just from eyeballing it.

[desertrek]

Had the same issue quite a few years ago towing a CJ7 with a fairly short class C. Take a look at your wheelbase length on your rig vs how much length hangs beyond the rear wheels. If the overhang beyond the rear wheels is excessive (anything over 1/3 the overall length of your rig) that could be the issue in a nutshell. A tough problem to overcome "inexpensive." The tail ends up wagging the dog due to the amount of force it takes to move the front wheels of the toad. On my fourth rig and I tow a grand cherokee right now and that is the first thing I now check before buying a new rig. Sorry this may not solve your issue but something to check.